Global Patent Index - EP 0378440 A2

EP 0378440 A2 19900718 - An image forming apparatus.

Title (en)

An image forming apparatus.

Title (de)

Bilderzeugungsgerät.

Title (fr)

Appareil de formation d'images.

Publication

EP 0378440 A2 19900718 (EN)

Application

EP 90300382 A 19900112

Priority

  • JP 476089 A 19890113
  • JP 11553289 A 19890509

Abstract (en)

An image forming apparatus includes a first developing device and a second developing device. The second developing device acts on an image bearing member already having a first toner image produced by the first developing device to form a second toner image. The second developing device has a developer carrying member to which a vibratory voltage is applied. A duty ratio of the vibratory voltage is controlled.

IPC 1-7

G03G 15/01; G03G 15/09; H04N 1/46

IPC 8 full level

G03G 15/01 (2006.01); G03G 15/09 (2006.01)

CPC (source: EP US)

G03G 15/0121 (2013.01 - EP US); G03G 15/0907 (2013.01 - EP US)

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0378440 A2 19900718; EP 0378440 A3 19901003; US 5066979 A 19911119

DOCDB simple family (application)

EP 90300382 A 19900112; US 46344390 A 19900111